Services that utilize a cloud system include a service that provides a virtual environment (virtual machine (VM)), for example. According to a request from a user of the virtual environment, upgrade of the virtual environment is performed on an upgrade date designated by the user.
A related technique is a technique of performing an update job of a physical machine after a backup job (see, e.g., Japanese Laid-Open Patent Publication No. 2010-4335). Another related technique is a technique of notifying a user of information (see, e.g., Japanese Laid-Open Patent Publication No. 2002-318978).
Nonetheless, the upgrade date designated by the user is not a date determined with consideration of information managed on a service provider side such as a planned backup date and a planned restore (restoration) date. Therefore, the upgrade date designated by a user is not necessarily a date suitable for performing the upgrade.
For example, it is assumed that a user designates, as an upgrade date, a date included in a period after a planned backup date and before a planned restore date. In this case, the restore returns the virtual environment to the state at the time of backup before the upgrade and therefore, the same upgrade must be performed again.
If upgrade is performed in this way, the service provider side must perform the same upgrade twice, causing a problem of increased maintenance management work. Meanwhile, this situation is inconvenient for the service user side because the virtual environment cannot be used during upgrade.
If the user refers to information managed by the service provider side, a suitable upgrade date can be determined. However, if the information managed by the service provider side is made public, a large number of users will use the virtual environment immediately before the planned backup date for data protection and therefore, an increased load on the virtual environment may make it impossible to provide stable service. Additionally, if the information managed by the service provider side is made public, unauthorized data may be added to data that is to be backed up and may threaten security. Therefore, a user cannot be allowed to refer to the information managed on the service provider side, in terms of the stable provision and security of the service.